反应详情

To a solution of diethyl (2-bromo-4,5-difluorobenzoyl)malonate (75.6 g) in water (100 ml) is added p-toluenesulfonic acid (0.3 g), and the mixture is refluxed for 3 hours. After cooling, the reaction mixture is extracted with dichloromethane. The dichloromethane layer is washed with saturated aqueous sodium chloride solution and dried over magnesium sulfate. After distilling off the solvent under reduced pressure, the residue is distilled to give ethyl (2-bromo-4,5-difluorobenzoyl)acetate (52.0 g), b.p. 105°-115° C. (0.15 mmHg).

1. temperaturethe mixture is refluxed for 3 hours
2. temperatureAfter cooling
3. extractionthe reaction mixture is extracted with dichloromethane
4. washThe dichloromethane layer is washed with saturated aqueous sodium chloride solution
5. dry with materialdried over magnesium sulfate
6. distillationAfter distilling off the solvent under reduced pressure
7. distillationthe residue is distilled